A rise in society's population that is concentrated primarily in major cities is known as Urbanization.
Urbanization may occur both from the population shift from rural to urban residency as well as by population growth within the cities and can be understood as the the gradual increase in the proportion of people living in urban areas as opposed to rural areas.
In 1918 H1N1 Or "The Spanish Flu" emerged and was extremely contagious. It was a Novel Virus just as SARS-CoV-2 (Coronavirus) is. Within months H1N1 spread to almost every country on the planet and was considered a Pandemic. The reason it was called "The Spanish Flu" is because Spain was the only country to report this in their news media. similar to what china tried to do by not reporting about the virus at first. The reason the 1918 was so deadly was because it emerged right as World War 1 ended and soldiers where moving all across the planet to return from the war to their home country which made the virus spread like wildfire and now with SARS-CoV-2 millions of people travel to the other side of the planet within hours daily which made it spread so fast.
People should consent to their government.
The statements that describe how Feudalism work is :
1. A lord would be given land by the king in return for homage or a promise to serve the king when called upon.
4. A vassal depended on the agricultural production of serfs to feed the whole system
5. A king would hire a vassal to provide an army and political advice during times of war